U.S. patent number 4,524,735 [Application Number 06/652,103] was granted by the patent office on 1985-06-25 for reciprocating piston engine.
This patent grant is currently assigned to Audi AG. Invention is credited to Armin Bauder.
United States Patent |
4,524,735 |
Bauder |
June 25, 1985 |
Reciprocating piston engine
Abstract
In a reciprocating piston combustion engine, an insert extends
substantially to the plane separating the leading part of the oil
pan from the interior of the crankcase. The free longitudinal edge
of the insert is disposed above the oil level in the oil pan.
Recesses in the insert receive oil that drips down from the
crankshaft bearing and directs it back to the oil pan. In view of
the close proximity of the recesses with the movement of the crank
web, very little oil reaches the insert.
Inventors: |
Bauder; Armin (Neckarsulm,
DE) |
Assignee: |
Audi AG (Neckarsulm,
DE)
|
Family
ID: |
6209637 |
Appl.
No.: |
06/652,103 |
Filed: |
September 19, 1984 |
Foreign Application Priority Data
|
|
|
|
|
Sep 21, 1983 [DE] |
|
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3334044 |
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Current U.S.
Class: |
123/196R;
123/198E; 184/106; 184/11.4; 184/13.1 |
Current CPC
Class: |
F01M
11/00 (20130101) |
Current International
Class: |
F01M
11/00 (20060101); F01M 001/00 () |
Field of
Search: |
;123/196R,196S,198E,195C
;184/106,13.1,11.4 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Cross; E. Rollins
Attorney, Agent or Firm: Kane, Dalsimer, Kane, Sullivan and
Kurucz
Claims
I claim:
1. Reciprocating piston engine, in particular for motor vehicles,
comprising a cylinder-crankcase (1) with a plurality of cylinders
(2) having central axes which lie in a common plane (14), a
crankshaft (3) supported by bearings (4) within said crankcase,
said crankshaft comprising crank pins (6) and crank webs (7), said
crankcase having a bottom opening (10) with longitudinal edges
extending parallel to the crankshaft, said opening (10) being
closed by an oil pan (11), and further comprising an insert (13)
between the crankshaft and the bottom of the oil pan, said insert
extending substantially over the whole length of the said bottom
opening, characterized in that said insert (13) extends from that
longitudinal edge (15) of said bottom opening (10), which lies in
the direction of rotation (D) of the crankshaft (3) behind the
plane (14) comprising the cylinder axes in opposite direction to
said direction of rotation (d) without interruption substantially
up to said plane (14) to separate the leading portion of the oil
pan from the interior of the crankcase.
2. Reciprocating piston engine according to claim 1, wherein said
insert (13) extends substantially up to said plane (14) only,
whereby a free edge (20) is formed which lies above the oil level
within the oil pan (11), said insert (13) having depressions (16)
underneath the crank bearings (4), said depressions (16) having
side walls (17) which extend close to the paths of the adjacent
crank webs (7), whereby the deepest spot (19) of the depressions
(16) lies on the free edge (20) of the insert (13).
3. Reciprocating piston engine according to claim 2, wherein said
insert (13) closely matches the paths (22) of the connecting rods
(8) between adjacent depressions (16).
4. Reciprocating piston engine according to claim 1, wherein said
insert (13a) extends from one longitudinal edge (15) of said bottom
opening (10a) to the other longitudinal edge (30), and wherein
openings (32) are provided in the region between the trailing edge
(30) and the plane (14a) containing the cylinder axes, so that oil
from the crank bearings (4a) can drip into the oil pan.
5. Reciprocating piston engine according to claim 1 or 4, wherein
said insert is screwed to the crankcase along the respective
longitudinal edge(s) (15, 15a, 30) of the bottom opening (10, 10a)
thereof.
Description
In a known combustion engine of this type (DE-OS No. 19 48 186), an
insert extends from the connecting path of the connecting rod from
a longitudinal edge of the lower opening of the cylinder crank
housing to the other longitudinal edge of the lower opening of the
cylinder crank housing; and, it is also provided with openings
adjacent these two longitudinal edges, so that the oil which is
taken along by the parts of the rotating crank shaft flows
downwardly in the space between the insert and the oil pan. Despite
the fact that the insert is adjusted to the path of movement of the
connecting rod and oil can collect in the lower area into which the
connecting rod heads preimmerse, because of the upper positions of
the opening in the insert, oil waste occurs despite the insert.
It now has been determined that even with reciprocating
piston-combustion engines, wherein the oil level in the oil pan is
normally disposed below the movement paths of the connecting rod
heads and the crank web, considerable losses occur due to the oil
loss. A test of this phenomenon showed that the air in the crank
case is taken along by the rotation of the crank shaft, the
connecting rod heads and the crank webs, thus resulting in
increased speed in the crank shaft in the rotational direction of
the crank shaft. A dynamic pressure is generated by this rotating
air which acts on the oil in the oil pan and displaces this oil in
the rotational direction of the crank shaft, so that it reaches the
area of movement of the connecting rod heads and the crank webs.
The insert of DE-OS No. 19 48 186 cannot prevent this displacement
of oil, since the dynamic pressure can act through the openings at
the one side of the insert on the oil in the lower disposed oil
pan; and, the area of the openings on the other side of the insert
suction is generated by the vortex which supports the transmition
of oil from these openings into the area of movement of the
connecting rod heads and the crank webs.
It is an object of the invention to reduce, in a reciprocating
piston-combustion engine of the foregoing type, the immersion of
the connecting rod heads and the crank webs into the oil, and,
thereby, the capacity loss is held to a minimum with the least
amount of effort.
This object of the invention is solved in that the insert extends
from the longitudinal edge of the bottom opening which lies in the
direction of the bottom opening, which in turn lies in the
direction of rotation of the crank shaft behind the plane
comprising the cylinder axes, in a direction opposite the direction
of rotation without interruption substantially up to the plane
separating the leading portion of the oil pan from the interior of
the crankcase.
In accordance with the invention displacement of the oil is
prevented in the area of the connecting heads and crank webs in the
oil pan by means of the dynamic pressure by the previously
mentioned vortex.
Preferably, the insert extends substantially to the plane
containing the cylinder center axis, whereby its free longitudinal
edge is above the oil level in the oil pan. The insert is provided
with recesses below the crank shaft bearing, whose side wall extend
close to the movement of the adjacent crank webs and whose deepest
location is provided at the free longitudinal edge of the insert.
Accordingly, about half of the injection oil which discharges from
the crank shaft bearings can reach the oil pan directly, while the
other half drips down to the recesses provided immediately below
the crankshaft bearing and can flow from there to the oil pan.
Since the sidewalls shift these recesses close to the operating
movement of the crank webs, only very little oil can reach the
insert in which the crank webs and the connecting rod heads
circulate.
In order to assure that distance is constantly provided between the
free longitudinal edge of the insert and the oil level which will
adjust during operation, thus preventing overflow of oil from the
oil pan into the insert, it is essential to adjust the insert in
cross-section, at least at its rear in a rotational direction, so
as to accommodate the path of movement of the crank webs and the
connecting rod heads, namely, to shape it in the form of a
quadrant, so that the oil displaced in the crankshaft can increase
behind or below the insert during acceleration, during driving up a
mountain as well as during the air movement, so that the oil level
is reduced in the area of the free longitudinal edge of the
insert.
In order to increase the stability of the insert, it can extend
from one longitudinal edge of the lower opening to the other, such
that in the area of the longitudinal edge of the lower opening of
the cylinder crankshaft following the rotational direction of the
crank shaft and the plane containing the cylinder center axis,
openings are provided for the discharge of the oil from the
crankshaft bearings into the lower positioned oil pan.
One exemplified embodiment of the invention with one deviation is
described in the following in relation to the drawings. The
drawings show:
FIG. 1 is a cross-sectional view of a cylinder crank housing of a
reciprocating combustion engine with flanged oil pan;
FIG. 2 is a view of the cylinder crank housing of FIG. 1 from
below, with the oil pan omitted;
FIG. 3 is a sectional view along the line 3--3 in FIG. 1;
FIG. 4 is a sectional view along line 4--4 in FIG. 1; and
FIG. 5 is a view similar to FIG. 2 with a different insert.
A cylinder crankshaft 1 is shown in FIG. 1 having a plurality of
cylinder bores 2 in which a crankshaft 3 is mounted by means of
bearings 4. The crankshaft 3 is composed of the base bearing pins 5
mounted in the bearings 4, the connecting rod bearing pins 6
disposed between the adjacent base bearing pins 5 and the crank
webs 7 which connect the connecting rod pins 6 with the base
bearing pins 5 in the form of balancing weights. The number of the
connecting rod pins 6 corresponds to the number of cylinder bores 2
and each connecting rod pin 6 is connected with a reciprocating
piston 9 by means of a connecting rod 8 and an associated cylinder
bore 2.
The cylinder crankshaft housing 1 is open at its bottom and its
lower opening 10 is closed by a flanged oil pan 11. In usual
manner, a suction basket 12 of a lubricating pump is connected to
the oil pan. An insert 13 is provided between the crankshaft 3 and
the bottom of the oil pan 11 which essentially extends throughout
the total length of the lower opening 10 of cylinder crankshaft
housing 1, as can be seen in particular in FIGS. 3 and 4, looking
at plane 14 in which the cylinder axes are disposed in rotational
direction D of crankshaft 3, up to the corresponding longitudinal
edge 15 of the lower opening 10 of the cylinder shaft housing 1.
The insert 13 is provided with recesses 16 below crankshaft bearing
4, whose side walls 17 extend in proximity to the operating
movements 18 of crank webs 7 and run parallel thereto, as can be
seen from FIG. 3. The deepest location 19 of each recess is
positioned on the free longitudinal edge 20 of insert 13. The
insert 13 is adjusted between the recesses 16 with its rear area in
the rotational direction D very close to the operating path 21
(connecting rod movement) of connecting rod 8 or the connecting rod
heads 8a, as can be seen from FIG. 4. Thereby pockets 22 are
created between adjacent recesses 16. The free edge 20 of the
insert 13 is within pockets 22 and at such a distance from the oil
level 23 that under no circumstances can oil flow from the oil pan
11 into pockets 22, and the pockets are deep enough so that no oil
can collect therein.
The injected oil which discharges from the crankshaft bearings 4
can reach the oil pan 11 directly through the area of the lower
opening 10 of the cylinder housing 1 which is not covered by insert
13. The remainder of the injected oil flows into the recesses 16
and can flow from there into the oil pan 11, since its deepest
location 19 is disposed at the free edge 20. The inclination of the
bottom of the recesses 19 with respect to the horizontal may be
about 3.degree. . Since the lateral limiting walls 17 of recesses
16 extend closely to the operating cycle 18 of the crank webs 7,
only a very low amount of oil can reach the are of movement of the
crankshaft 7 and into pockets 22. The small amount of oil which can
collect in the pockets 22 is taken along with the connecting rod
heads 8a and centrifuged into the oil pan 11. If need be, a
discharge bore may be provided at the deepest position of each
pocket 22. The insert above all, prevents oil from being displaced
into the right part of the oil pan 11 as viewed in FIGS. 3 and 4
due to the rotating movement of crank shaft 3, and, prevents the
oil from being displaced by the rotating movement of crankshaft 3
from oil pan 11 in the rotation D of the crank shaft.
Without the insert 13, one would obtain the oil level 24 shown in
dot-dash lines in FIG. 4, whereby the connecting rod heads 8a would
immerse in the oil. This is effectively avoided by the insert 13.
Due to the adjustment of insert 13 to the operational paths 18 or
21 of the crank webs 7 and the connecting rod 8 or the connecting
rod heads 8a at the rear area in the rotational direction D, the
oil displaced thereby can increase under the insert 13, whereby the
oil level is lowered in the area of the free edge 20 of the insert
13, so that the protection against overflow of oil into pockets 22
is increased, and in particular the free edge 20 is very deep in
the area of pockets 22, so as to keep the oil level as low as
possible in the pockets 22. The insert 13 also prevents oil
reaching the area of movement of the connecting rod or the
connecting rod head heads in the driving direction behind the
cylinder during ascending movements and during aceleration.
The insert 13 may consist of sheet metal or plastic and is screwed
onto the lower side of the cylinder crank housing 1 by means of
screws 25.
The alternate embodiment of FIG. 5 differs from the one of FIG. 2
essentially only in that the insert 13a extends from the one
longitudinal edge 15a to the other longitudinal edge 30 of the
lower opening 10a of the cylinder crank housing 1a and is provided
with openings 32 for the discharge of oil from the crank shaft
bearings 4a into the lower positioned oil pan in the area between
the longitudinal edge 30 and the cylinder center axis plane 14a.
The ribs 31 which are formed thereby stiffen the longitudinal edge
19a and prevent a vibration thereof during operation. Preferably,
the ribs 31 are mounted in the same plane of the crankshaft bearing
4a, however, they are considerably smaller, so that the oil
discharge is not prevented by these ribs 31.
* * * * *